We have Two shaft frame3 Gas Turbine installed at our plant commissioned in 1985 whose control system was upgraded in 2014 to MARKVIe by GE. Turbine is loaded with Seimens two Compressors through a gear box. Recently GT overhauled inhouse and successfully maintenance carried away. After maintenance completion a week before, unit attempted to start, however unit tripped on LP SHAFT LOCKED alarm at 55% HP SPEED.
Everything startup sequence seems to normal, e.g., Fire at 24%, Accelerating normally, fuel gas pressure, fuel flow, PCD, Servo valves, exhaust temp are normal.
This is happened first time, we rechecked LP TURBINE speed pickups found normal. Is there any other cause plz advise?
Plz. Note that a year before we have upgraded compressors and gearbox too. After that machine started successfully many times.
Everything startup sequence seems to normal, e.g., Fire at 24%, Accelerating normally, fuel gas pressure, fuel flow, PCD, Servo valves, exhaust temp are normal.
This is happened first time, we rechecked LP TURBINE speed pickups found normal. Is there any other cause plz advise?
Plz. Note that a year before we have upgraded compressors and gearbox too. After that machine started successfully many times.